1. Field of the Invention
The present invention relates to a digital copying machine. More specifically, the present invention relates to a digital copying machine capable of accomplishing image formation on paper at an optional reserved time.
2. Description of the Related Art
Conventional copying machines present disadvantages inasmuch as when a certain operator has a large volume of copying to be done, this operator engages the sole use of said copying machine for a long period during which said copying machine is unavailable for use by other operators. One technique for eliminating the aforesaid disadvantage is a copying machine disclosed in U.S. Pat. No. 4,708,461. This copying machine provides an automatic document feeder(hereinafter referred to as "ADF") having a plurality of document trays on which can be placed reserved original documents (original documents to be copied at a reserved time range). At a predetermined reserved time, this copying machine automatically feeds reserved original documents from the document tray and transports said original documents onto a document glass platen, and executes a copying operation.
However, the aforesaid copying machine disclosed in the U.S. Patent has certain disadvantages inasmuch as the reserved original documents are left occupying the document tray until the reserved time range. These disadvantages are described below:
(1) Other operators may be unaware that the aforesaid original documents are reserved documents, and may possibly remove the reserved original documents from the document tray; PA1 (2) an operator Cannot take measures to correct document feed trouble (e.g., original jam) in the ADF because original documents are fed when the operator is away from the area; PA1 (3) the copying machine cannot be reserved by a plurality of operators (copying operations cannot be performed during optional reserved times). PA1 image reading means for reading image of said original document and for generating image data corresponding to the image of said original document; PA1 memory means for storing said image data read by said image reading means; PA1 image forming means for forming image on a sheet based on said image data stored in said memory means; PA1 clocking means for clocking time; PA1 judging means for judging whether or not the time being clocked by said clocking means reaches a predetermined time; and PA1 controlling means for controlling said image forming means to start the image formation on a sheet based on said image data stored in said memory means when the time being clocked by said clocking means reaches the predetermined time.
Among the aforesaid three disadvantages, the third (3) disadvantage can be eliminated by providing a plurality of document trays. However, the provision of a plurality of document trays increases the cost of the copying machine. The embodiments of the copying machine disclosed in the aforesaid U.S. Patent are limited to two document trays due to restrictions in construction.
A further disadvantage unrelated to the previously described problems, is that the reserved copying cannot be accomplished when the main switch of the copying machine is turned off.